While the invention relates broadly to the connection of parallel shafts at the interior of a machine housing by means of an endless drive belt, it is of special value in connection with the headstock drive system for a turning center or lathe. Most lathes have an input shaft for a headstock motor drive, coupled to a system of change gears and shafts at the interior of the lathe headstock for transmitting power to the headstock spindle, which comprises an output shaft. The headstock spindle is used for supporting and driving a workpiece of revolution during machining operations. The headstock shafts of a lathe are frequently very heavy and are fixedly mounted at both ends into precision bearings located within the headstock housing. Due to the weight and complexity of mounting, disassembly of the shafts is very time consuming and quite laborious.
In a production turning machine, where frequent geared speed changes are not required, it is known to connect the input, or driving shaft, to the spindle, or driven shaft by means an endless belt; for example, a timing belt. Timing belts are very reliable and give good service, but when it is necessary to replace the endless timing belt, the disassembly of the driving and driven shafts is a cumbersome and time consuming task which necessitates a long, expensive downtime for the machine.
The present invention obviates the difficulties inherent in the prior machine assemblies.